Portable head rest



FIG. 1 is a left rear perspective view of a portable head rest;

FIG. 2 is a right side view of a portable head rest;

FIG. 3 is a left side view of a portable head rest;

FIG. 4 is a rear side view of a portable head rest;

FIG. 5 is a front side view of a portable head rest;

FIG. 6 is a overhead view of a portable head rest; and,

FIG. 7 is a bottom view of a portable head rest. 

CLAIM The ornamental design for a portable head rest, as shown. 